Several experts on the subject had less desirable takes, like that the life of a celebrity can be extremely lonely despite being popular.

"You become hypersensitive to what is said about you," social media expert Kinsey Schofield told Fox News at the time. "Your circle of friends becomes much smaller and you always find yourself playing the role of what people want because you’re afraid of being irrelevant or normal again."

Plenty of former stars return to ordinary lives and seem to be doing just fine — or maybe they’re not.

Here’s a list of stars who’ve effectively left the spotlight, either intentionally or otherwise, after relatively prolific careers.

1. Bettie Page

Page ended her modeling career permanently after finding God.
(AP)

Called the “Queen of Pinups," Page was at the height of her career when she left the public eye. The New York Times previously reported public disdain on pornography and "other pressures" compelled the model to retire. However, she was later sent to a mental institution after a charge of reportedly attacking a landlady and eventually committed to evangelicalism. Although she only modeled in the '50s, her image and likeness still continues to thrive in pop culture. "I'm more famous now than I was in the 1950s," Page said in a 2006 interview with The Los Angeles Times. She died in 2008 at age 85.

Duvall became an immediate favorite of filmmaker Robert Altman’s after her first role in his 1970 comedy “Brewster McCloud.” She earned acclaim for her quirky style through the 70s, but her best-known role is probably for playing Wendy Torrance in Stanley Kubrick’s classic horror film, “The Shining.” Duvall continued to appear in film and television through the '90s and even produced television shows and albums aimed at children. She maintained a low profile after her last film role in 2002, until her emergence in 2016 through a controversially broadcasted interview with Dr. Phil that exposed her apparent mental illness. The Actors Fund reached out to Duvall following the interview to get her appropriate treatment, Deadline reported at the time.

4. Lauryn Hill

Nothing else has come from the immense potential Hill showed through her first and only solo album.
(Reuters)

Since the dissolution of her '90s hip-hop group, Fugees, the singer-rapper recorded only one solo album, “The Miseducation of Lauryn Hill.” She set the bar extremely high for herself as the album received five Grammys and 10 nominations. The 43-year-old couldn’t replicate the quality with her subsequent material and she only released a few more songs to date. In a 2010 interview with NPR, Hill said she stopped recording music for several cryptic reasons, including an unsupportive environment. It's also conjectured that her six children have kept her busy. Despite her lack of recent material, her sole album stands as an inspiration to popular contemporary artists, including Beyoncé and Adele.

5. Syd Barrett

Reports speculate regular use of psychedelic drugs played a significant role in Barrett's mental decline.
(Zuma Press)

Barrett was the original frontman of Pink Floyd, one of the most commercially successful music groups of all-time. But his declining mental health, reportedly a result of his regular use of psychedelic drugs, prompted him to leave the band in 1968. In an interview with Rolling Stone, Pink Floyd's drummer, Nick Mason, said Barrett would stand still during live sets as if he wasn't mentally there. "Syd was losing interest in the whole thing and we were carrying him around," Mason said about the approaching conclusion of Barrett's tenure in the band. Barrett went on to record two solo albums with the help of Pink Floyd members, each of whom reported considerable difficulty working with him in his deteriorated state. He lived the rest of his life in seclusion until his death at 60 years old in 2006. The progressive rock band's 26-minute epic “Shine on You Crazy Diamond” pays homage to Barrett.

6. Jack Gleeson

As things stand, Gleeson will be most remembered as Joffrey in "Game of Thrones."
(Zuma Press)

Gleeson, 26, said he wanted to pursue an education after his run as the cruel Joffrey Baratheon in “Game of Thrones” for the show’s first four seasons. Several media outlets construed this as a proclamation of retirement, but he's since dismissed the rumors in an interview with The Music. His acting days can still technically be considered over, however, as he's not made an on-screen appearance since his "Game of Thrones" stint from 2011 until 2014.

7. Greta Garbo

Garbo is considered one of the greatest even though she stayed quiet for most of her life.
(AP)

Born in Sweden, Garbo was one of Hollywood’s most popular stars during the late silent film and early “talkie” eras, until she received overwhelming negative scrutiny for her lead role in the 1941 rom-com “Two-Faced Woman.” Garbo announced her retirement thereafter at age 36. Even during her short career, she led a reclusive life; she never signed autographs, answered fan mail or attended premieres. Garbo reportedly planned to return to Hollywood after World War II, but nothing materialized. Despite her relatively early exit from the spotlight, she was ranked 5th in the American Film Institute’s 1999 list of the greatest female film legends. She died in 1990 at 84 years old.

8. Richard Simmons

For a traditionally loud individual, his current lifestyle raises questions.
(Reuters)

Simmons earned popularity for his flamboyant and enthusiastic persona in promoting weight loss both through video programs and his own gym, but his recent and sudden slide into the shadows has been of particular intrigue. Given the 69-year-old has not made a public appearance since 2014, conspiracy theories have arisen on his well-being. There's even a six-episode podcast dedicated to investigating Simmons' mysterious disappearance. It's easy to jump to the conclusion that something strange happened to the once boisterous Simmons, but he's made phone calls to media outlets to clear up any legitimate suspicions.